FABRICATION OF IRON-ALUMINUM CHROMIUM ALLOY FUEL PLATES
0
Citation
0
Reference
20
Related Paper
Abstract:
ABS>Briefly discussed are the characteristics (oxidation resistance, moderate cross section, and adaptability to reprocessing) that recommend Fe-Al alloys for use as cladding materials for gas-cooled core components, and the metallurgical peculiarities (brittleness, joining difficulties, and marginal hot strength) that have limited their use in the past. The properties of a newlydeveloped Fe-Al base alloy (71/2 wt.% Al, 5 wt.% Cr, 1 wt. % Cb, 1/2 wt.% Ti, remainder Fe) in which the deficiencies of older materials have been largely eliminated are summarized. Exploratory studies involving the fabrication by hot- roll bonding of dummy fuel elements are described; this work consisted of bonding the alloy described above to itself, to a 302B stainless steel-UO/sub 2/ cermet, and to a 0.20 wt,% C steel-Al/sub 2/O/sub 3/ cermet. Steps in assembling the elements, using a modified picture frame technique, are covered briefly. Methods for removing surfuce oxides from element components are discussed; it is concluded that mechanical abrasion is most satisfactory. Edge welding of assemblies before rolling them is recommended to avoid oxidation of interfaces. The development of hotrolling procedures capable of insuring complete bonding of components is described; rolling and heattreatment schedules are presented in tabular form. Photomicrographs illustrating the recrystallization bondsmore » obtained between core and clad and in the deadend portions of elements are included. A moderate amount of data is presented on the preparation of FeAl base matrix materials, using powder metallurgical techniques, Comparisons are made between methods of obtaining powdered alloys (elemental powders, master alloys, and other techniques). Pressures and sintering temperatures employed in iorming compacts are discussed. Also covered is the cold rolling of the sintered compacts. The bend ductility and oxidation resistance of the rolled strips is correlated with their metallurgical histories. Test results, photographs, and photomicrographs are included. (auth)« lessKeywords:
Cermet
Cladding (metalworking)
Cite
In general alloying elements are added in Iron to enhance its mechanical, electrical, attractive and tribological properties. Phosphorus is a vital alloying component in steel, since it was discovered. The addition of phosphorus content in the low carbon steels results in viably enhancement of the strength. Phosphorus additionally enhances wear resistance, magnetic properties and corrosion resistance of steel. Fe-P steels have been processed through wrought as well as powder metallurgy route. However, production of Fe-P steels through wrought processing route is troublesome due to tendency of phosphorus to isolate along the grain boundaries during solidification. Phosphorus segregation along the grain boundaries in cast route can be avoided by alloy designing. Fe-P steels have been developed through powder metallurgy route. High density Fe-P steels have been developed through powder pre-form technique. This high strength steel is valuable in basic structural applications such as to make rebars for reinforcement, corrugated sheets for roofing, flats, angles, beams, trusses etc. Fe-P steels are less expensive to existing high strength good wear and good corrosive materials.
Powder Metallurgy
Carbon fibers
Cite
Citations (1)
The review contains main directions in the development of modern steelmaking, hot rolling technologies and heat treatment aimed to follow increased requirements to seamless tubes for production of oil and gas under severe conditions. New targets of PJSC “Gazprom” in development of new resources have determined new technical requirements to pipes for low temperature application, resistant to hydrogen sulfide and carbon dioxide corrosion. Basic metal science approaches are given to develop new chemical compositions of high quality steels containing minimum of sulfur, phosphorous and solute gases. Corresponding heat treatment routes are determined for formation of martensitic microstructure in full wall section during quenching with subsequent high tempering for required combination of high strength and ductility. It was shown that optimal combination of high strength and toughness at 60 °C below zero can be achieved by alloying of chromium-molybdenum steel containing about 0.25 wt. % of carbon with strong carbon forming elements such as vanadium and niobium. Sustainability of these steels to stress sulfide cracking was achieved through grain refinement with microalloying by molybdenum in concentrations corresponding to strength grades that gives high hardenability and retards tempering of martensite. New compositions of corrosion resistant martensitic 13 % chromium steel were carried out that was resulted in required resistance to carbon dioxide environments with improved low temperature toughness and high strength. The authors present results of reconstruction of steel making and hot rolling production lines at JSC “Volzhskii Pipe Plant” providing the required quality of new products from continuously cast steel billets to finished tubes.
Tempering
Hardenability
Ductility (Earth science)
Cite
Citations (0)
The use of spark plasma sintering technique has been identified as a means of enhancing materials properties, especially nickel-based alloys. Nickel and nickel-based alloys are essential materials that combine different properties which include; high-temperature strength, good mechanical properties, appreciable toughness, resistance to thermal shock, resistance to thermal fatigue, resistance to chemical attack, resistance to creep, resistance to corrosion/oxidation and good surface stability at the high-temperature environment. The above qualities have made alloys gain more patronage and acceptance in recent time. However, a higher percentage of the demand comes from the aerospace industry, gas/steam power plant, petrochemical plant, nuclear reactors and marine industry. Spark plasma sintering is one of the powder processing methods in metallurgy that has been used to fabricate nickel-based alloys with exceptional qualities. The process involves, mixing metallic powders to form the desired stoichiometry composition (in the case of forming an alloy), either by direct mixing or mechanical alloying. The already mixed powder is transfer to a graphite mould and then compacted in the heating chamber of the furnace. Heat is supply to sinter the compacted powder at a temperature below the alloy melting point, in order to ensure metallurgical bonding between the powder particles. The application of spark plasma sintering technology is a promising one, especially for processing nickel alloys. It promotes the formation of gamma (γ) matrix phase, gamma prime (γ') intermetallic phases, secondary gamma prime (γ") intermetallic phase and precipitation of solid solution strengthening elements. These are the phases that improve the mechanical properties of sintered alloys. Spark plasma sintering minimizes the problems associated with conventional fabricating routes such as; micro segregation, pores and pin holes.
Spark Plasma Sintering
Powder Metallurgy
Cite
Citations (28)
Food packaging, structural components in the aerospace industry, and other uses for aluminized aluminium alloys are just a few of the many uses for this abundant metal. Because of its low weight, moderate strength, and high corrosion resistance, aluminium and its alloys have found widespread use in a wide range of industries. Aluminum alloys of the 7xxx series have superior mechanical qualities when compared to other aluminium alloy series. The alloy AA7075 is utilised in the structure of aircraft wings. When fusion welding is used to combine certain alloys, they are more prone to solidification or hot cracking. The alloying components present contribute to these alloys' high crack sensitivity. Thus, a rigorous analysis has been undertaken in this project effort to determine how to reduce the susceptibility of the alloy 7075 to hot cracking by adjusting the composition without affecting the mechanical qualities. A thorough background study has been conducted on the effect of hot cracking on the aluminium alloy AA7075, and a methodology for overcoming this welding defect has been developed. This methodology includes altering the composition of the major alloying elements in AA7075 and stabilising the composition for the development of a new alloy. Experiments were conducted and alloys were cast with a predetermined composition. The samples were subjected to a hot cracking test, and the sample with the best result had its mechanical properties determined. The test results were compared to those obtained with AA7075 and discussed in this paper.
6063 aluminium alloy
Fusion welding
Alonizing
Cite
Citations (0)
The main task of this work was to study the effect that they have different contents of silicon, manganese, magnesium and titanium in aluminum alloy 6082 on the yield strength and tensile respectively. 6082 aluminum alloy is used for rims for road vehicles. Replacement of aluminum alloy steel has a number of advantages including the following may be mentioned: aluminum has a much lower density than steel is easy to process, is characterized by good physical and mechanical characteristics, related to the density, and high corrosion resistance. Aluminum alloy wheels can be obtained by casting or plastic deformation.
Alonizing
6063 aluminium alloy
Cite
Citations (0)
Welded joints with corrosion-resistant steels and heat-resistant alloys, which require different modes of heat treatment to achieve the level of mechanical properties specified in the design documentation, are used for the manufacture of parts and components of the turbo-pumping unit (TNA) and liquid rocket engine. Heat-resistant alloys are called a large group of alloys on iron, nickel and cobalt bases with the addition of chromium and other alloying elements (C, V, Mo, Nb, W, Ti, Al, B, etc.), the main feature of which is to maintain high strength at high and cryogenic temperatures. Heat-resistant alloys are used in the manufacture of many parts of gas turbines in rocketry and jet aircraft, stationary gas turbines, the pumping of oil and gas, hydrogenation of fuel in metallurgical furnaces and many other installations. For the doping of nickel chromium γ-solid solution, several elements are used, which differently influence the increase of heat resistance and processability. Along with the main reinforcing elements (Ti, Al), refractory elements (W, Mo, Nb) are introduced into the alloy, which increase the thermal stability of the solid solution. Heat resistant alloys based on cobalt. Cobalt has a positive effect on the heat-resistant properties of alloys. The introduction of chromium in cobalt increases its heat resistance and hardness. In addition to chromium, alloys containing cobalt contain additives of other alloying elements that improve their various properties at high temperatures. A characteristic feature of these alloys is that they have relatively low heat resistance characteristics at moderate temperatures, which, however, change little with the temperature up to 900 ° C and therefore become quite high compared to the characteristics of other heat-resistant alloys. A significant drawback of these alloys is their high cost due to their high cost of cobalt. Nickel-based heatresistant alloys typically have a complex chemical composition. It includes 12–13 components, carefully balanced to obtain the required properties. The content of impurities such as silicon (Si), phosphorus (P), sulfur (S), oxygen (O) and nitrogen (N) is also controlled. The content of elements such as selenium (Se), tellurium (Te), lead (Pb) and bismuth (Bi) should be negligible, which is provided by the selection of charge materials with low content of these elements, because to get rid of them during melting does not appear possible. These alloys typically contain 10–12 % chromium (Cr), up to 8 % aluminum (Al) and titanium (Ti), 5-10% cobalt (Co), as well as small amounts of boron (B), zirconium (Zr) and carbon (C). Molybdenum (Mo), tungsten (W), niobium (Nb), tantalum (Ta) and hafnium (Hf) are sometimes added. Heat-resistant alloys are used for the production of many parts of gas turbines in rocketry and jet aircraft, stationary gas turbines, for pumping oil and gas products, for hydrogenation of fuel in metallurgical furnaces and in many other installations. Nickel-based heat-resistant alloys are also cryogenic, i.e. they are capable of operating and retaining mechanical properties at very low temperatures (-100 ° C to -269 ° C). Such alloys are chromium-nickel alloys having an austenitic structure. Not only do they have good mechanical properties that do not change over a large temperature range (-200 ° C to 900 ° C), they can also work in corrosive environments. Nickel-based heat-resistant alloys typically have a complex chemical composition. It includes 12–13 components, carefully balanced to obtain the required properties. Welded and combined workpieces are made of separate components that are interconnected by various welding methods. Welded and combined blanks greatly simplify the creation of complex configuration designs. Improper workpiece design or incorrect welding technology can lead to defects (grooves, porosity, internal stresses) that are difficult to correct by machining. Given that finding replacements with multiple materials, working them out in production, and investigating interconnectivity during thermal forces in a product can take considerable time and money, it would be best to replace one alloy, and unifying the material used would allow the structure to work. as a whole, which would increase the manufacturability of the products. After examining the different replacement options, inconel 718 was selected for the study. Studies of welded specimens of inconel 718 alloy-stainless steel for resistance to the ICC have shown that welded inconel 718 alloy joints with 12X18H10T steel and 316L steel after high temperature heating during soldering and subsequent aging in aggressive environments. Thus, on the basis of working conditions and technical requirements for the impeller, it is advisable to use material that would ensure uninterrupted operation in a corrosive environment at cryogenic temperatures. Based on the working conditions of the parts, it is most expedient to make it from heat-resistant chromium-nickel alloys, namely, from float inconel 718 which meets the necessary strength characteristics, has been investigated The recommended soldering mode is heating up to 950 ± 10oC, holding for 30 minutes from the moment of loading into the oven, cooling to 3000C with the oven, further in the air, since it has less influence on the corrosion resistance of steels in stainless steel joints. Quality control of inconel 718 alloy by GOST methods similar to that used for the control of X67MBHT type alloys showed results similar to those obtained by the ASTM and AMS control methods.
Inconel
Cite
Citations (0)
Cite
Citations (0)
The ever increasing demand from aerospace industries and automotive industries to manufacture components which are lighter and stronger than conventional steel has prompted the significant usage of aluminium alloys. This research work involves the investigation of mechanical properties in aluminium alloys before and after cold work forged. Major alloying elements used in the aluminium alloy are manganese and silicon. The aluminium alloy ingots are prepared through gravity casting. After the ingots are air cooled to room temperature, they are work hardened using cold forging method. The cold forged aluminium alloys are then subjected to tensile tests, wear tests, hardness tests and microstructure analysis using optical Scanning Electron Microscope (SEM). The material properties achieved are compared with the alloys properties that have not been subjected to work hardening. The expected outcome is to achieve a work hardened aluminium alloy that exhibits excellent wear resistance property which can be best suited for numerous industrial manufacturing requirements. It is observed that broken Mn after forging has shown better wear resistance property having toughness property.
6063 aluminium alloy
Work hardening
Die casting
Tensile testing
Cite
Citations (0)
Cast aluminium-silicon alloys containing graphite particles are
reported to offer the potential for use as bearing and cylinder block
materials due to low friction and wear characteristics, good thermal
conductivity and resistance to corrosion. However, a fundamental problem
exists in dispersing graphite particles because liquid aluminium alloys
do not wet graphite and so particles are rejected by the melt.
The first section consists of a literature survey which examines
the potential for graphite aluminium alloys, and reviews various methods
for dispersing graphite particles. The potential for the use of recently
developed methods of casting semi-solid alloys as a means of retaining
graphite particles in melts is then considered.
The second section reports on an investigation into the production
of aluminium-silicon alloys which contain graphite particles and an
evaluation of the mechanical and tribological properties of the composites
produced with various silicon and graphite contents. Processing semisolid
alloys produced an even dispersion of graphite particles without
segregation, agglomeration or rejection. Solidification under pressure
(squeeze casting) was used to optimise the mechanical properties of the
composites. The evaluation of mechanical and tribological properties showed
that strength and ductility were reduced in alloys which contained
graphite. Wear tests showed that graphite additions provided increased
load carrying capacity, reduced coefficient of friction, reduced steady
running temperature and reduced damage to mating components. There
was no evidence of a deterioration in corrosion from corrosion tests
and machinability tests showed that machinability was greatly improved
by the addition of graphite particles.
Machinability
Ductility (Earth science)
Cite
Citations (0)
The influence of titanium amount and pouring temperature on the structure and properties of lean-alloyed alloy was explored. It was determined that lean titanium-alloyed aluminum alloys have better mechanical and electrical properties, which is explained by formation of heat-resistant dispersoids in solid solution. It was found that an increase in the amount of titanium by more than 0.5–0.6 % has a negative influence on electrical properties of the aluminium-based alloy. It was revealed that formation of four types of phases in complex-alloyed Fe and Si alloys contribute to preservation of tensile strength.The results of comparative studies of ingots and wires from experimental and mass-produced alloys were given. Results of experimental research on determining the modes and parameters of deformation and thermal treatment and their influence on mechanical and electrical properties of aluminum alloys were presented. They made it possible to develop the technology of production of lean titanium-alloyed aluminium-based alloy and rolling electrical products from it. During its implementation it was found that aluminum ingots, cold-treated sheets and wires, retain the necessary strength and minimal specific electrical resistance at high enough temperatures. A positive effect of cold deformation and intermediate annealing on formation of the rational structure and a good combination of electrical and mechanical properties of the products was revealed
Titanium alloy
Alonizing
Cite
Citations (0)